Actuation balls are used to drive downhole tools. For example, actuation balls may be launched to drive a hydraulic sleeve. Hydraulic sleeves are used in various tools and include an annular seat on the sleeve that is formed to accept and catch a suitably sized ball thereon. When a ball lands thereon, a seal is formed between the ball and the sleeve that inhibits fluid flow therepast such that a hydraulic pressure can be built up above the ball, such hydraulic pressure being suitable to move the sleeve along the tubular in which it is installed. One possible sleeve and ball system is described in U.S. Pat. No. 6,907,936 of Jun. 21, 2005 to the assignee of the present application. While actuation ball is the general term, some such balls do not have a typical spherical “ball-like” structure and it should be understood that the structure may be closer in shape to a dart or plug.